SAS devices usually include one or more ports. A port usually includes one or more transfer paths (phys). A port including one phy is called a narrow port, and a port including two or more phys is called a wide port. A state where a plurality of phys inside a wide port is used as the same transfer path is called a wide link. With the wide link, a plurality of command frames can be transmitted/received concurrently between an initiator device (hereinafter referred to as initiator) and a target device (hereinafter referred to as target).